Manufacture of semiconductor integrated circuits is gearing towards surface mount technology, in which, integrated circuits are formed in packages that are then singulated into individual devices. Examples of these packages are ball grid arrays (BGA) and chip scale packages (CSP). These integrated circuits are often formed on a leadframe or substrate. For example, the leadframes/substrate comes in strips and may vary in widths from about 25-80 mm and lengths from about 140-270 mm.
These packages are often tested and laser marked before being delivered; these machines are generally automated and they process thousands of packages or strips an hour. For a machine to handle a range of semiconductor packages, the handler and associated clamps must accommodate a range of widths of leadframes on which the packages are removeably mounted. Currently, some machine suppliers provide a change kit for each package type and/or leadframe/substrate; when a machine is configured to handle a particular package and/or leadframe, the machine's handler is equipped with a change kit that has a clamping unit associated with the particular package and/or leadframe. A disadvantage of changing the handler with a change kit is that it takes manual effect and time to carrying out the change. Human intervention may introduce errors following the change.
In one approach, U.S. Pat. No. 6,958,917, assigned to Fuji Machine Mfg., Ltd., describes a fragile substrate holding device. The holding device has a contact portion of a receiving member and moveable member being made of an elastically deformable material such as rubber. The holding device may also have a velocity reducing device.
It can thus be seen that there exists a need for a simple and robust device to adaptively hold or clamp the leadframe/substrate of integrated circuit packages during manufacture. Preferably, the clamp device is automated and dispenses with human intervention.
FIG. 1 shows a conventional laser marking machine 5. As shown in FIG. 1, the laser marking machine 5, similar to that illustrated in U.S. Pat. No. 7,155,299, issued to the present assignee, includes an input pick-and-place handler 10 operable in a Y-direction to pick a strip of integrated circuit (IC) package W one at a time from an input magazine 20. Each IC package W is then moved to an input station 40 of a conveyor 30. At the input station 40 is a clamping device 42 for holding the IC package for it to be moved along the conveyor 30. As shown in FIG. 1, the conveyor 30 consists of three sections, namely, an input track 32, a marking track 34 and an output track 36.
Along the marking track 34 is a pre-marking inspection station 50, a laser marking station 52 and a post-marking inspection station 54. The processed IC packages W are then transferred to an output station 60 on the output track 36. At the output station 70 is an output pick-and-place handler 80 operable to move the processed IC packages W to an output magazine 70.